1. Field of the Invention
The present invention relates to a cardiovascular analysis system, and more specifically to a cardiovascular analyzer which enables to detect cardiovascular diseases early and to define their causes. Unlike conventional electrocardiographs, in each branch of the blood vessels of left and right coronary arteries, the cardiovascular analyzer can further measure elastic coefficient of blood vessel (i.e., arterial stiffness) showing organic change, compliance of blood vessel showing organic and functional changes simultaneously, and volume, resistance and velocity of blood flow showing resistance characteristics of blood flow.
2. Description of the Related Art
In the present day, the incidence of vascular and cardiovascular diseases such as arteriosclerosis and myocardial infarction is rapidly increasing due to the meat-oriented dietary lifestyle. But the technology and the instrument for recognizing and preventing the diseases previously are poor.
In today's clinics, the electrocardiograph can't be used to early find out the ischemic diseases and to analyze the function of cardiac blood vessel. Also, the image processing technology and the angiography can be used to diagnose the apparent patient with the diseases because they only show the images of the cardiac blood vessel.
In order to early recognize the symptom of cardiovascular disease such as myocardial infarction, the determination of the coronary artery property, the blood flow characteristics and the blood state is more useful than that of the images of cardiac blood vessel and the electrocardiogram.
The state of blood is easily determined by the blood test. However, the determination of the property of coronary artery and the characteristics of blood flow needs new analyzing instrument.
The most important issue is an exact determination of characteristics of coronary artery. Unlike the other blood vessels, the coronary artery causes vasospasm and vasodilation by the external factors and the epidemiology relationship is complicated with the action of inside pressure of the coronary artery. Consequently, it is very difficult to obtain the properties and characteristics such as arterial stiffness, vascular compliance, blood flow volume, blood flow velocity and blood flow resistance in the coronary artery.
The automatic analyzing electrocardiograph system is widely used in clinics, but it is unable to early find out the risk of incidence of the coronary artery diseases and to determine the patient to surgery by a noninvasive testing method. The electrocardiogram records the electrical changes in the heart but not record the biodynamical properties of cardiac blood vessel such as elastic coefficient of blood vessel, compliance of blood vessel, and volume, resistance and velocity of blood flow.
The coronary artery disease analyzers developed until now are a single photon emission computerized tomography (SPECT), a contrast echocardiography (CE), a multidetector CT (MDCT) and a magnetic resonance imaging (MRI).
On purpose to apply into the surgery of coronary artery, the invasive testing method as catherization has an advantage to directly observe the pathological changes of blood vessel itself but has a need of an essential and complex invasive manipulation of blood vessel. About 40% of examinees have been revealed to person without a need of that surgery.
The electrocardiograph is principally unable to exactly diagnose the ischemic diseases of coronary artery.
Additionally, the mentioned devices have a clinical significance but, owing to high manufacturing and diagnostic cost, are able to be used in the particular hospital only. Commonly, the mentioned devices are unable to detect the properties of blood vessel in spite of little difference.
The property of blood flow in a left coronary artery differs from that of blood flow in a right coronary artery. The blood vessel of left coronary artery is pressed with an additive internal pressure because of the systolic tissue-pressure by the contraction of ventricular myocardium.
Consequently, because the blood flow of the left coronary artery has a very complex structure, the pressure waveform causing the blood flow in the left coronary artery is covered until now.
The right coronary artery perfuses the right ventricle.
The systolic pressure of the right ventricle is about 30% of that of the left ventricle. The pressure of systolic coronary artery is comparably smaller in the right ventricular myocardium.
The invasive testing methods have been widely studied to measure an additive internal pressure transferred from a systolic tissue-internal pressure produced by an intrinsic myocardium contraction in coronary artery. However, until now the noninvasive testing method is insignificantly used to develop the instrument for measuring blood flow volume, blood flow velocity, vascular compliance, elastic coefficient of blood vessel, and blood flow resistance in the coronary artery.
During the last 10 years, the blood flow property of coronary artery has been widely studied and it was found out the blood flow of left coronary artery runs only during the diastole.
At the same time, Japanese researchers discovered that the blood flow also runs during the diastole in the capillary vessel of coronary artery by the radioisotope insertion method.
On the other hand, the property of blood vessel has also been studied. In 2006, Korean and American scientists suggested a method to calculate an elastic coefficient of artery. This method is to calculate an elastic coefficient of blood vessel by measuring atheroma but is difficult to apply to the coronary artery. In addition, in 1997, Ridker and his colleagues of Harvard University have shown that high-sensitivity C-reactive protein has a relationship to cardiovascular diseases. Based on the above study, in 2006, j-CHROMA™ method has been developed to observe the disease process but has not provided information on the state of blood vessel.
However, the present invention provides the measuring methods of blood flow, compliance of blood vessel, blood flow velocity, blood flow resistance, and stiffness of artery (i.e., the degree of arteriosclerosis) in left and right coronary arteries by the synchronous analysis of the electrical property of heart and the biodynamic property of coronary artery.
In order to measure blood flow volume, compliance of blood vessel, blood flow velocity, and blood flow resistance in each branch of left and right coronary arteries, the first issue is to obtain an aortic arch internal pressure curve using the noninvasive testing method.
One related method to obtain the aortic arch internal pressure curve using the noninvasive testing method had been suggested in the international patent publication No. WO1995/016391 (METHOD AND APPARATUS FOR TREATING CARDIOVASCULAR PATHOLOGIES). However, because the curves obtained by the above method are very different from those of the invasive testing method in the same patient, it is virtually impossible to coincide with those curves.
Consequently, it is really impossible that the aortic arch internal pressure curve obtained by the method of WO1995/016391 is extrapolated into clinical trial as like as that curve obtained by using the invasive testing method.